This invention relates to a hand operated pump and filter assembly for transferring and filtering low viscosity fluids, such as hydraulic oils, transmission fluids, some motor oils, etc.
With modern hydraulic machinery the components that pump and control the machine have critical clearances of down to about 0.0003 inch. Contamination of the hydraulic oil causes accelerated wear in the high performance components of such systems.
It is known in the bearing industry that bearing life is extended when the hydraulic oil is properly filtered. Hydraulic component manufacturers will not always honor component warranties if the oil does not meet ISO 4406 specifications.
A number of hydraulic oil transfer pumps have been used, but none have addressed the problem of pushing the oil through a fine (ten micron) filter to keep contamination out of high performance components with clearances of about 0.0003 inch.
It is an object of this invention to provide a hand operated pump for transferring low viscosity fluids from supply containers to a fluid reception point.
It is a further object of this invention to provide a hand operated pump and filter assembly for transferring low viscosity fluids from supply containers to a fluid reception point.
It is a still further object of this invention to provide a hand operated pump and filter assembly for transferring hydraulic oil from a supply container through a ten micron or less filter to machinery having components which require close tolerances.
These and other objects are achieved by providing a manually operated Dump that acts as a combination vacuum and displacement pump.
The pump of the invention has a barrel with inner and outer cylindrical walls, the inner cylindrical wall forming a central passageway extending between an inlet end and an outlet end.
A cylindrical piston rod is positioned with its inner end being located within the e central passageway of the e barrel and its outer end outside the central passageway of the barrel, the piston rod and barrel having a common longitudinal axis. The outer cylindrical wall of the barrel has a longitudinally extending vent groove machined therein to allow air to enter a fluid supply container as fluid is being pumped out of it.
The outer end of the piston rod is attached to a handle for manually raising and lowering the piston rod during the upstroke and downstroke, respectively.
A piston is attached to the inner end of the piston rod. The piston has at least one fluid passageway extending therethrough, the passageway having an associated valve means for closing the passageway during an upward stroke of the piston rod and opening the passageway during a downward stroke of the piston rod.
The inlet end of the barrel has valve subassembly means for opening communication between the exterior of the barrel and its central passageway during an upstroke and closing communication during a downstroke.
A lock adapter for attaching the pump to a fluid oil supply container is provided. The adapter is slidably attached to the outer cylindrical wall of the pump barrel and is threaded to lockingly engage the threads of the outlet of a supply container.